The only chance a team from any other conference has of making the playoffs is to go undefeated.
I don’t think this is a reasonable concern, as there really isn’t much track record for it that isn’t at least somewhat justifiable. Incidentally the B1G is the conference that his has happened to the most, by a large margin. I have looked into it before, here is the history of 1 loss teams in power 5 conferences + notre dame as it pertains to being left out of the playoff:
- Most recently, Notre Dame with 1 loss was left out for an undefeated cinci (2021).
- There were three during the covid season, 1 was from the SEC (a&m), 1 was from the b1g (Indiana), and one played only 6 games that year in the pac (USC) (2020). That is if you even want to count this incomplete year in this.
- In 2018 there were three undefeated power 5 teams that made the playoff, and a 1 loss team from the big 12 got in over a 1 loss team from the big 10.
- In 2017 the 1 loss big 10 runner up did not get in over 1 loss alabama, who joined one loss teams from the ACC, big 12, and Georgia. This is probably your best supporting omission of a 1 loss team, except that it was a B1G team, and Alabama ended up winning the playoff that year.
- In 2015 two 1 loss teams from the big 10 didnt make the playoff (Iowa and Ohio State), instead it was one loss michigan state, oklahoma, alabama, and undefeated clemson.
- in 2014 two one loss big 12 teams were left out (baylor and TCU), but they played 1 less game with no conference title game than the three 1 loss teams and one undefeated team that made it (alabama, oregon, florida state, ohio state)
Scoreboard is:
Pac: 1
ACC: 0
Big 12: 2
SEC: 1
Big 10: 5
Notre Dame: 1